Low pour point mineral oil composition



Patented Sept. 8, 1936 LOW Pom Pom MINERAL on. ooMrosrnoN Adrianna Johannes van Peakl, Bussum, Netherasslgnor to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing.

This invention relates to the methods of .lowering pour points of mineral oils, and is particularly concerned-with the class of viscous lubricating oils containing waxy constituents. I

The invention resides in the discovery that certain organic compounds upon being added to mineral oils in, very minute quantities markedly lower the pour points of these mineral oils. The

eflectcf addingsuch substances to mineral oils the secondary mono- -poly-amino-ary1 compounds may may be determined by various methods, such, for example, as A. S. T. M. Method D 9'7-27T.

According to this invention the active organic substances to be used for lowering the pour points of mineral oils, 1. e. the substances possessing pour point reducing properties, are built up of cyclic nuclei and aliphatic side chains, the latter containing at least one oxygen or nitrogen atom, preferably in such a way that if the substance contains only one nucleus at least two side chains are present and if the substance contains more than one nucleus at least one side chain is present. These products are for example obtained as reaction products of the fatty acids and/or alcohols with cyclic compounds whose molecules contain two or more primary amino, and/or one or more secondary-amino and/or hydroxy, and/or poly-hydroxy, and/or amino-hydroxy groupings. The monoorpoly-cyclic nuclei to which'one or more radicles of a fatty acid and/or an alcohol are attached may be either heterocyclic or carbocyclic. The nitrogen atom or atoms connecting the cyclic nucleus with the fatty acid radicles may be either within the nucleus as in azines or oxazines, or attached directly to a carbon atom of the nucleus.

Among various nitrogen-containing compounds or poly-amines and particularly the primary poly-amines were found to be suitab e for producing. in combination with the higher fatty acids (or better, with their anhydrides, or correspondingacyl-halides)- the pour point reducing substances. For example, amon'g such suitable compounds may be mentioned: 0-, or m-, or p-phenylene-diamine's, or triamino-, or tetramino-benzenes, also their homologues with one or more alkyl side chains, such as diamino toluenes, diamino-methylethyl benzene, diamino- Q xylenes, triamino-toluenes, triami'n'o-ethyl benrenes, triamino-xylenes, triamino-azo-benzene. hydrochloride (Bismarck brown), etc. Rep'resenting the secondary monoaminoand secondary be mentioned: diphenylamine, methylaniline, and their homologues, methyl aminoaniline, dimethylphenylene diamine, phenylaniline-amine methylphenyl Application Julyl, 193:, Serial No. In the Netherlands July 5, 1932 phenylene-diamine, and their homologues. The group NH, as has been stated, may be positioned within the nucleus of the molecule, as for example in benzopyrrole, or indole, or in indigo.

It is to be understood that tertiary amines may 5 be used for the purpose of this invention, provided, however, that they contain a primary and/or secondary amino groupings in addition to the tertiary one.

The above enumeratedgroups of nitrogen-containing compounds, and particularly such compounds as 1,3,phenylene diamine, indigo, and Bismarck brown, were found .to produce, when allowed to react in conventional manner with fatty acids, or their anhydrides, or corresponding 15 acyl halides, substances possessing properties of lowering the pourpoints of mineral oils containing waxy constituents. Such -reaction products are known to be amides of the acids used in the reactions, such as anilides. j

Referring now to the oxygen-containing groups of the compounds suitablejfor the purpose of the present invention, these were stated to include hydroxy-, polyhydroxy-, and amino-hydroxycyclic compounds, which may be; represented by 25 such specific examples from aromatic series as: phenol, diand/or tri-hydroxy benzenes and their homologues, mono-, or di-,-- or tri-hydroxy naphthalenes, or mono-, and/or poly-hydroxy-anthrarcenes, or mono-,' or pgly-hydroxy-anthraquinones, and their homologues; also compounds of the aurine group, such as aurine (a trihydroxytriphenyl-methane) compounds of hydroxyamino-benzene and hydroxy-polyamino-benz'ene groups, etc. 35

In order to obtain the desired pour point reducing substances, the oxygen containing compounds are made to react in a known manner with the higher fatty acids (or their anhydrides, or acyl halides), such as stearic, palmitic, or cerotic acids,

and/or with one or more of the lower and/or higher aliphatic primary, secondary or tertiary alcohols, which may be either mono--, or polyhydroxy, and either saturated or unsaturated. The resulting products of reaction may be either 45 ketones or ethers or esters, or amido-salts of the fatty acids used in the reaction, or mixed ethers or esters and amide-salts.

It should be noted that this invention is not dependent upon or limited to the particular methods of obtaining thesubstances possessing pour point reducing properties, but is directed to the use of such substancesregardless of the methods of their manufacture, In other words, even though these substances are defined in this specl- 55 Oils Pour point reducing substance Percent wt. adde Rlllllllaflflll o gmu p.p. +2 0.

Borneo org. P-p.+8 O.

Lowering oi pour points, 0., from the original Distearyl m-pbenylene di- .5

amine. Stearyl compound of Bismarck .5

brown. Stearyl compound of indigo--. 'leirastearyl compound oi triaminophenol. Resorcincl-disteerflto Pyrogalloi-tristearate Pyrogallnl-trist-enr' Pbloroglucinol-tristearate. Distearlte oi 1,6,dioxy-naphthalene. i0. Aurlne-distearate ll. Trioxy-triphenylrnethane-tristearate. 12. Distearylallzarine 13. Rufigullic acid-hexastearate..

lace

cum

DID- OIOI In addition to the above described groups of substances distearylnaphthalene the dimyricyl ether of 1,5,dioxynaphthaiene and the cerotic acid ester of cholesterol were found very suitable for lowering pour points of mineral oils.

The products of reaction between a fatty acid, such as stearic acid, in the presence of AlCla, and the condensation products of naphthalene, such as described by Homer in the Journal of the Chemical Society of London, Transactions, 1907, vol. XCI, part II, page 1103, were found to be very effective pour point reducers, whose addition in quantities of about .5% by weight to the Roumanian, Pennsylvania, and Borneo oils lowered their respective pour points by 27 C., 25 C. and 9 C.

In general, the extent to which the pour point can be reduced by means of a particular substance depends upon the nature of the oil to be treated, so that some substances have a greater effect on one oil than on another. Some substances may have no effect on certain oils, but reduce the pour points of others. The most effective pour point reducer can be easily ascertained in each case by actual trials by using some of the various substances which have been described above. The optimum quantities of the selected pour point reducers may vary for different oils, but usually do not exceed 1% by weight of the oil.

It has been found that petroleum sulphonic acids, i. e. those kinds thereof in which the sulphonic acid groups have entered into the arcmatic nucleus of the molecule, can be converted into the corresponding phenols, by dissolution with potassium hydroxide and that compounds of the type according to this specification can be prepared therefrom by etherification or esterification with derivatives of high molecular alcohols or acids, which compounds can then be used as pour point reducers.

The compounds of the type described in this specification can be used not only to lower the pour points of natural and synthetic lubricating oils but can be used to lower the pour points of other hydrocarbon oils, for example, fuel oils, gas oils, tar oils, shale oils and residues.

The compounds can advantageously be used in oil wells with a view to avoiding crystalline paraffin wax deposits.

I claim as my invention: v

l. A mineral oil composition comprising a mineral oil and a small proportion of ruflgallic acid hexastearate.

2. A mineral oil composition comprising a mineral oil containing waxy constituents in quantities sufficient normally to cause an undesirably high pour point and a small quantity of a compound having an organic cyclic nucleus and a side chain of the formula R-C(O)O--R' where R- represents a high-molecular organic radical containing said high molecular aliphatic chain and -R' represents an organic cyclic nucleus, at least two radicals of the group consisting of ester, keto, ether and amido radicals being linked to R when R represents a single monocyclic nucleus.

3. A mineral oil composition comprising a mineral oil containing waxy constituents in quantities sufficient normally to cause an undesirably high pour point and a small proportion of an ester of a higher fatty acid and an organic cyclic compound, said ester containing at least two aliphatic side chains each linked to said cyclic compound through an ester group when said cyclic compound contains only one monocyclic ring structure.

4. A mineral oil composition comprising a mineral oil containing waxy constituents in quantities suflicient normally to cause an undesirably high pour point and a small proportion of an ester 01 a higher fatty acid and an organic carbocyclic compound, said ester containing at least two aliphatic side chains each linked to said cyclic compound through an ester group when said cyclic compound contains only one monocyclic ring structure.

5. A mineral oil composition comprising a mineral oil containing waxy constituents in quantities suflicient normally to cause an undesirably high pour point and a small quantity of resorcinol distearate.

6. A mineral oil composition comprising a mineral oil containing waxy constituents in quantities suflicient normally to cause an undesirably high pour point and a small quantity of pyrogallol tristearate.

ADRIANUS JOKANNES VAN PESKI. 

